Apparatus for coating selected portions of the surface of a base material



Nov. 14, 1961 c. J OWEN APPARATUS FOR COATING SELECTED PORTIONS OF THE SURFACE OF A BASE MATERIAL Filed Sept. 10, 1957 Fri CECE DEBUG; QDUUUQ QDUUDQ EMBED; EDDUUQ DEBUG; QUDDUQ QUUUUQ UBUUUQ :33 13 E QJ a.

//v VEN me CHARL E5 .1. OWEN Ma A from ey 3,008,892 APPARATUS FOR COATING SELECTED PORTIONS on THE SURFACE OF A BASE MATERIAL;

Charles J. Owen, Pittsburgh, Pa., assignor to United States Steel Corporation, -a-corporation of New J ersey:

Filed Sept. 10, 1957, Ser. No. 683,098

4 Claims. (Cl. 204-,-207). v

This invention relates to apparatus for coating selected portions of the surface of a base material. In the coating of selected portions of the surface of 'a base material such as the coating of steel strip with another metal an aqueous solution of the salt of the coating metal is generally'used as the electrolyte. In addition to thesaltandwater the electrolyte may include addition agents. The electrolytes of which I have knowledge aresuch that-theylwill flow readily and hence cannot be'applied on an inclined surface or in a specific pattern.

It is therefore an object of my invention to provide apparatus for continuously coating selected portions of a movingstrip. f f

These and other objects will be more apparent after referring to the following specification and attached drawings,inwhi ch: M v

FIGURE his a schematic view of the apparatus of my invention; I p H FIGURE 2 is a view of a roll used in the apparatus of FIGURE lglandr v FIGURE 3 is a schematic view showing another. form of apparatus which may be'used in' the practice of my invention;

Referring'rnore panticularly'to'FIGURES landZof the drawingsjthe reference numerals ,2 and 4 indicate conductor'rolls over which a strip S to'be coated passes. The roll 4 is connected to a-soureeer negative current 6. An'eng'raved'roll 8 is located between the rolls 2 and 4 and is connected to a source of'positive 10. The rolls 2 and 4 also serve to holdthe strip S in close contact with the roll'8." The roll 8is' preferably made of stainless steel with a "thin" hard non-conducting material '12 I over its outersurface with depressions 14 therein extending down to thesbainless steel. The depressions 14 form the design which is to be applied to the strip S. A container 16 is located beneath the roll 8 and contains the electrolytic mixture of my invention. A feeder roll 18 is in contact with the electrolytic mixture and with the roll 8. The feeder roll 18 may be provided with brushes or other means for taking the electrolytic mixture from the container 16 and delivering it to the roll 8. A doctor blade 20 bears against the roll 8 so as to remove any excess of the electrolytic mixture therefrom. From the roll 4 the strip passes through a water spray 22 downwardly to a roll 24, then upwardly through pinch rolls 26 to a drying tower 28 and over roll 30. Suitable conventional means such as bridle rolls 31 may be provided for moving the strip S through the processing equipment. The roll 18 is also rotated in any suitable manner, such as by means of a motor 32.

The operation of this apparatus is as follows: As the strip S moves through the processing equipment all of the rolls will rotate and the electrolytic mixture will be applied to the roll 8 to fill the depressions 14 therein. The doctor blade 20 scrapes away the excess viscous electrolytic mixture on the surface of the roll 8 leaving the depressions 14 filled to the outer surface of the roll. Plating current passes from roll 8 through the electrolytic mixture in the depressions 14 to the strip S depositing the metal ion contained in the electrolyte on the strip S. Current is carried away firom the strip by the roll 4. As the coated strip passes the water spray 22 excess electrolytic mixture is washed from the strip. The surface of the strip S is dried as it passes through the drying tower 28.

The apparatus as shown in" FIGURE 1 ma be used for several ,dilferent 'If thestrip S is tin plate therol-l 8 may be engravedfwith a' trademark, identi fying marks. or any other de sired design. Radio and electronic-instrument circuit patterns may be applied on' surfaceractivated non-conductors in strip form. Tin may be applied to the edges, of strip to be used in the manufacture of tin cans soas to fiacilitate soldering.

) The apparatus shown in FIGURE 3 is particularly adapted for depositing heavyfcoating and/or applying intricate patterns to a base material. The reference nu meral 34 indicates a'sheet to be plated and it is connected to a sourceof negativecurrent 36. A base block 38 is connected to a source of positive current 40. Base block 38 has -a detachable sheet ,42 of' the plating. metal 'onthe' lower surface thereof which is covered with af'thinhard non-conducting material '44 similar to the coating material 12 onthe roll 8. Depressions 46 extend through they material 44 to the sheet'42. I

In the'operation of this: device the electrolytic mixture of, fny invention is rolled into the depressions- 46 and the excess scraped from the non-conducting surface 44. Block 38 is then placed on the surfaceof sheet 34 with the coating 44 in contact therewith. Currentis applied to the system'and the coating material is deposited on the sheet 34 with the design being fonnedby the depressions 46. The electrolytic mixture may'also be used to patch adamagedplated'surfacej.

The'electrolytic mixture of my inventionpomprises from 1'to"7 6% by weight of the usual electrolyte, from 22 to 80% by weight of a miscible gum with the remain gums except the alg'in colloid are available commercially in ready form; The. algi'n colloid is usuallyi sold as 'e'powder and is prepared as a 4,to 10% by weight of the powder (preferably 6% with water and allowing the mixture-to gel overnight. All of these gums are not misciblev with all of the conmion ele'c trolytes, but no difficulty is encountered in selecting one of the group which will be miscible with the electrolyte being used. Examples of common electrolytes used in the coating process include Watts type nickel, which is a mixture containing from 240 to 450 g./l. of nickel sulfate, 37.5 to 60 g./l. of nickel chloride and 30 to 50 g./l. of

. boric acid; organic bright nickel, which is a mixture containing from 240 to 350 g./l. nickel sulfate, 37.5 to 60 g./l. nickel chloride, 30 to 50 g./l. boric acid, 5 to 10 g./l. nickel benzene disulfonate and 0.1 to 0.2 ml./l. triaminotolyldiphenylmethane; acid tin which is a mixture containing from 36 to 72 g./l. tinsulfate, 8 to 25 g./l.

. phenolsulfonic acid and 4 to 8 g./l. dihydroxydiphenylpotassium hydroxide. A specific electrolytic mixture of h I sulfone; acid copper which is a mixture containing from 180 to 260 g./l. copper sulfate, 45 to g./l. sulfuric acid; acid zinc which is a mixture containing from 180 to 360 g./l. zinc sulfate, 2 to 30 g./l. aluminum sulfate, 0 to 30 g./l. ammonium chloride, 0 to 15 g./l. sodium acetate and 0.5 to 1.5 g./l. licorice; and alkaline tin, which is a mixture containing from 75 to 250 g./l. potassium stannate, 30 to g./l. tin metal and 7.5 to 25 gJ/l. free weight of miscible gum which may be gumambic with the remainder being substantially all water; 4.5 to 76% by weight of acid copper'electrolyte and from 22 to 80% by weight of miscible gum which may be purified Indian gum with the remainder being substantially all water; 4 to 76% by weight of acid zinc electrolyte and from 22 to 80% by weight of miscible gum which may be starch base paste with the remainder being substantially allwater; and 2.5 to 76% by weight of alkaline tin electrolyte and from 22 to 80% byweight of miscible gum which may be water soluble algin colloid with the remainder being substantially all water.

vWhile several embodiments of my invention have been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

1. Apparatus for continuously coating selected portions of an electrically conducting strip which comprises two spaced apart rolls arranged in tandem, a source of negative current connected to one of said rolls, a source of positive current connected to the other of said rolls, said last named roll being made of conducting material With a non-conducting surface thereon and having depressions therein extending through said non-conducting surface,

means for directing the strip around a substantial arc of each of said rolls, and means for filling said depressions with an electrolytic mixture including from 1 to 7 6% by weight of an electrolyte, from 22 to 80% by weight of a miscible gum and the remainder substantially allwater and usual addition agents; r

2. Apparatus for continuously coating selected portions of an electrically conducting strip which comprises two spaced apart rolls arranged in tandem, a source of negative current connected to one of said rolls, a source of positive current connected to the other of said rolls, said last'named roll being made of conducting material with a non conducting surface thereon and having depressions therein extending through said non-c'onducting surface, means for directing the strip around asubstantial arc of each of saidrolls, a container adjacent said lastnan'led roll containing an electrolytic mixture including from 1 to 76% by weight of an electrolyte, from 22 to 80% by weighlt of a miscible gum and the remainder substan tially all water and usual addition agents, a feeder roll in contact with said electrolytic mixture and said last 4.. named roll, a wiper for removing excess electrolyte from said second named roll, means for spraying water on the strip after it has been coated to remove excess electrolyte, and means for drying said; coated strip.

3. Apparatus for continuously coating selected portions of an electrically conducting strip which comprises two spaced apart rolls arranged in tandem, a source of negative current connected to one of said rolls, a source of positive current connected to the other of said rolls, said last named roll being made of conducting material with a non-conducting surface thereon and having depressions therein extending through said non-conducting surface, means fior directing the strip around a substantial arc of each of said rolls, and means for filling said depressions with an electrolytic mixture. a v

4.' Apparatus for continuously coating selected portions of an electrically conducting strip which comprises two spaced apart rolls arranged in tandem, a source of negative current connected to one of said rolls, a source of positive current connected to the other of said rolls, said last "named roll having depressions therein, means for directing the strip around a substantial arc of each of said rolls, a container adjacent-said last named roll containing an electrolytic mixture, a feeder roll extending from saidcontainer to said last named roll to feed the elec trolytic mixture, a wiper for removing excess electrolyte from said second named roll, means for spraying water on the strip after it has been coated to remove excess electrolyte, and means for drying said coated strip.

7 5 References Cited inthe file of this patent 2 UNITED STATES PATENTS- Great Britain 4- of. 1843. 

1. APPARATUS FOR CONTINUOUSLY COATING SELECTED PORTIONS OF AN ELECTRICALLY CONDUCTING STRIP WHICH COMPRISES TWO SPACED APART ROLLS ARRANGED IN TANDEM, A SOURCE OF NEGATIVE CURRENT CONNECTED TO ONE OF SAID ROLLS, A SOURCE OF POSITIVE CURRENT CONNECTED TO THE OTHER OF SAID ROLLS, SAID LAST NAMED ROLL BEING MADE OF CONEUCTING MATERIAL WITH A NON-CONDUCTING SURFACE THEREON AND HAVING DEPRESSIONS THEREIN EXTENDING THROUGH SAID NON-CONDUCTING SURFACE, MEANS FOR DIRECTING THE STRIP AROUND A SUBSTANTIAL ARC OF EACH OF SAID ROLLS, AND MEANS FOR FILLING SAID DEPRESSIONS WITH AN ELECTROLYTIC MIXTURE INCLUDING FROM 1 TO 76% BY WEIGHT OF AN ELECTROLYTE, FROM 22 TO 80% BY WEIGHT OF A MISCIBLE GUM AND THE REMAINDER SUBSTANTIALLY ALL WATER AND USUAL ADDITION AGENTS. 